1250
V. Alagarsamy et al
compounds were also evaluated for their sedative potential by into ice water. The solid obtained was filtered, washed with
measuring the reduction in locomotor activity using an acto- water, dried and recrystallized from an ethanol/chloroform
photometer.
(75:25) mixture. Yield 78%, mp 142–145°C; IR (KBr) cm−1:
1
1683 (C=O), 1610 (C=C); H NMR (CDCl3) d (ppm): 2.5
(s, 3H, SCH3), 3.87 (s, 3H, OCH3), 7.0–8.26 (m, 8H ArH);
MS (m/z): 298 [M+]; Anal. calcd for C16H14N2O2S: C, 64.41;
H, 4.72; N, 9.38. Found: C, 64.53; H, 4.67; N, 9.45.
Materials and Methods
Chemistry
2-Methylsulfanyl-3-(4-chlorophenyl)-3H-
quinazolin-4-one (5b)
Melting points were determined in open capillary tubes on a
Thomas Hoover apparatus and are uncorrected. IR spectra
were recorded in KBr on a Shimadzu FT-IR, 8300 spectrome-
ter (cm−1), mass spectra were recorded on a MASPEC msw
9629 mass spectrometer at 70 eV, and 1HNMR spectra were
recorded on a Varian 300 MHz spectrometer, using tetrameth-
ylsilane as internal standard. Elemental analyses were performed
on a Carlo erba 1108 instrument.
This was prepared using the method described above. Yield
80%, mp 136–139°C; IR (KBr) cm−1: 1680 (C=O); 1H NMR
(CDCl3) d (ppm): 2.7 (s, 3H, SCH3), 7.3–8.4 (m, 8H ArH);
MS (m/z): 302 [M+], 304 [M++2]; Anal. calcd for
C15H11N2OSCl: C, 59.50; H, 03.66; N, 9.25. Found: C,
59.53; H, 03.61; N, 9.31.
2-Hydrazino-3-(4-methoxyphenyl)-3H-quinazolin-
4-one (6a)
3-(4-Methoxyphenyl)-2-thioxo-2,3-dihydro-1H-
quinazolin-4-one (4a)
2-Methylsulfanyl-3-(4-methoxyphenyl)-3H-quinazolin-4-one
(5a) (0.01 mol) was dissolved in ethanol (25 mL). To this,
hydrazine hydrate (99%) (0.1 mol) and anhydrous potassium
carbonate (100 mg) was added and refluxed for 30 h. The
reaction mixture was cooled and poured into ice water. The
solid obtained was filtered, washed with water, dried and
recrystallized from a chloroform/benzene (25:75) mixture.
Yield 74%, mp 196–200°C; IR (KBr) cm−1: 3350, 3320
A solution of 4-methoxy aniline (1) (0.02 mol) in dimethyl-
sulfoxide (DMSO) (10 mL) was stirred vigorously. To this
was added carbon disulfide (1.6 mL) and aqueous sodium
hydroxide (1.2 mL; 20 mol) dropwise during 30 min with stir-
ring. Dimethylsulfate (0.02 mol) was added gradually, keep-
ing the reaction mixture stirred in freezing mixture for 2 h.
The reaction mixture was then poured into ice water. The
solid obtained was filtered, washed with water, dried and
recrystallized from ethanol. Methyl anthranilate (0.01 mol)
and the above-prepared N-(4-methoxyphenyl)-methyl dithio-
carbamic acid (0.01 mol) were dissolved in ethanol (20 mL).
Anhydrous potassium carbonate (100 mg) was then added
and refluxed for 21 h. The reaction mixture was cooled in ice.
The solid separated was filtered and purified by dissolving in
10% alcoholic sodium hydroxide solution and reprecipitated
by treating with dilute hydrochloric acid. The solid obtained
was filtered, washed with water, dried and recrystallized from
ethanol. Yield 80%, mp 296–300°C; IR (KBr) cm−1: 3218
(NH), 1680 (C=O), 1593 (C=C), 1200 (C=S); 1H NMR
(CDCl3) d (ppm): 3.88 (s, 3H, OCH3), 7.0–8.1 (m, 8H, ArH),
10.36 (s, 1H, NH); MS (m/z): 284 [M+]. Anal. calcd for
C15H12N2O2S: C, 63.36; H, 4.25; N, 9.85. Found: C, 63.29;
H, 4.21; N, 9.91.
1
(NHNH2), 1674 (C = O); H NMR (CDCl3) d (ppm): 3.79
(s, 3H, OCH3), 4.95 (s, 2H, NH2), 6.82–8.06 (m, 8H, ArH),
8.56 (s, 1H, NH); MS (m/z): 282 [M+]; Anal. calcd for
C15H14N4O2: C, 63.82; H, 4.99; N, 19.84. Found: C, 63.71;
H, 4.95; N, 19.93.
2-Hydrazino-3-(4-chlorophenyl)-3H-quinazolin-4-
one (6b)
This was prepared using the method described above. Yield
83%, mp 162–165°C; IR (KBr) cm−1: 3360, 3300 (NHNH2),
1
1680 (C= O); H NMR (CDCl3) d (ppm): 4.98 (s, 2H, NH2),
6.93–8.12 (m, 8H, ArH), 8.73 (s, 1H, NH); MS (m/z): 286
[M+], 320 [M++2]; Anal. calcd for C14H11N4OCl: C, 58.64;
H, 03.86; N, 19.54. Found: C, 58.60; H, 03.82; N, 19.59.
4-(4-Methoxyphenyl)-4H-[1,2,4] triazolo [4,3-a]
quinazolin-5-one (I)
3-(4-Chlorophenyl)-2-thioxo-2,3-dihydro-1H-
quinazolin-4-one (4b)
The 2-hydrazino-3-(4-methoxyphenyl)-3H-quinazolin-4-one
(6a) (0.01 mol) and formic acid (25 mL) were mixed in a
round-bottomed flask and refluxed for 34 h, cooled and
poured into ice water. The solid obtained was filtered, washed
with water, dried and recrystallized from ethanol. IR (KBr)
This was prepared using the method described above. Yield
74%, mp 319–321°C. IR (KBr) cm−1: 3210 (NH), 1690
(C=O), 1210 (C=S); 1H NMR (CDCl3) d (ppm): 7.5–8.2
(m, 8H, ArH), 10.36 (s, 1H, NH); MS (m/z): 288 [M+], 290
[M++2]. Anal. calcd for C14H9N2OSCl: C, 58.23; H, 03.14;
N, 9.70. Found: C, 58.32; H, 03.11; N, 09.74.
1
cm−1: 1684 (C=O), 1607 (C=N); H NMR (CDCl3) d (ppm):
3.9 (s, 3H, OCH3), 7.1–8.4 (m, 8H, ArH), 8.6–8.7 (s, 1H,
ArH); MS (m/z): 292 [M+]. Using this procedure, compounds
II–X were prepared.
2-Methylsulfanyl-3-(4-methoxyphenyl)-3H-
quinazolin-4-one (5a)
The 3-(4-methoxyphenyl)-2-thioxo-2,3-dihydro-1H-quinazo-
lin-4-one (4a) (0.01 mol) was dissolved in 40 mL of 2% alco-
1-Methyl-4-(4-methoxyphenyl)-4H-[1,2,4] triazolo
[4,3-a] quinazolin-5-one (II)
holic sodium hydroxide solution. To this, dimethylsulfate IR (KBr) cm−1: 1707 (C=O), 1605 (C=N); 1H NMR (CDCl3)
(0.01 mol) was added dropwise with stirring. Stirring was d (ppm): 2.5–2.6 (s, 3H, CH3), 3.6–3.7 (s, 3H, OCH3), 7.0–8.1
continued for 1 h and the reaction mixture was then poured (m, 8H, ArH); MS (m/z): 306 [M+].